In-vivo measuring systems are known in the art. Some autonomous capsule like in-vivo devices, which traverse the gastrointestinal (GI) system, may include an imaging sensor, or imager, for imaging (e.g., capturing images or taking pictures of) the interior of the GI system. An in-vivo device may include one or more imagers and/or sensors of other types (e.g., pH sensor, pressure sensor, temperature sensor, etc.), and/or various types of tools (e.g., micro electro-mechanical system, or “MEMS”), for example to perform surgical operations in vivo and/or to administer medication in the GI system, for example from a container contained in an in-vivo device.
While in operation (e.g., after swallowing), an in-vivo device may wirelessly exchange data with an external (extra-body) receiver. For example, the in-vivo device may wirelessly transmit data (e.g., sensory data; e.g., image data pertaining to captured images) to the external receiver, and the external receiver may wirelessly transmit instructions back to the in-vivo device, for example instructions which depend on data transmitted from the in-vivo device. For example, the in-vivo device may transmit image frames to the receiver, and the receiver may transmit an instruction to the in-vivo device, for example, to change the images' capturing rate, for example, based on captured images.
The length and anatomically-inhomogeneous nature of the GI system—it is about five meters long and it has anatomically distinct sections such as the small intestine and the large intestine—and the way in which the GI tract is situated within the body tends to detrimentally affect wireless communication between the in-vivo device and the external receiver when the in-vivo device reaches certain locations within the GI tract. This detrimental effect, in part, results from the relatively low transmission power that an autonomous, self-contained, in-vivo device uses, and also because body tissues (e.g., muscle tissues, tissues of the GI organs, bone tissue, etc.) interfere with the communication. A poor communication channel may result in noisy communication and even in loss of data (e.g., image data). For example, the in-vivo device may transmit an image but, in a poor communication environment, the receiver might not receive the image.
The communication problem described above is further exacerbated by the massive bone structure of the pelvis that supports the GI organs (e.g., the small intestine, the large intestine) and is even less pervious to radio waves than the soft body tissues. Heretofore, antennas setups/layouts have been designed to enable fairly good communication, between a swallowed in-vivo device and an external receiver, when the in-vivo device is in the upper section/part of the GI system, and, therefore, the effect of the pelvic bones on the quality of communication is relatively low, negligible, or non-existent. U.S. Pat. No. 5,604,531, filed Jan. 17, 1995, entitled “IN VIVO VIDEO CAMERA SYSTEM”, U.S. Pat. No. 7,618,366, filed Mar. 8, 2005, entitled “ARRAY SYSTEM AND METHOD FOR LOCATING AN IN VIVO SIGNAL SOURCE”, and U.S. Pat. No. 7,650,180, PCT application filed Jul. 4, 2004, entitled “IMAGING SENSOR ARRAY AND DEVICE AND METHOD FOR USE THEREOF” show typical conventional antenna setups. However, the detrimental effect of the pelvis bones on the communication's quality is by far noticeable when the in-vivo device is in the lower section/part of the GI system, where the pelvis bones have the strongest detrimental effect on the communication quality, and the conventional antenna setups used for the communication have been found to be far from optimal, or unsuitable, for sensing signals that originate from a signal source residing in the pelvis.
Since the lower section of the GI tract in general, and the lower part of the colon in particular, is of special clinical interest because of its susceptibility to diseases, it would be beneficial to have an antenna setup that improves wireless communication between the in-vivo device and the external receiver while the in-vivo device traverses the lower section/part of the GI tract, and in every area of the GI tract.
Conventional antenna arrays include antenna elements that are planar ‘loop’ antennas. One problem with planar ‘loop’ antennas is that these antennas are directional and they have a relatively sharp null, and, in general, such antennas have a radiation pattern that is similar to a radiation pattern of a dipole antenna. Being directional and having a sharp null, the communication between a swallowed in-vivo device and an antenna element is susceptible to the location of the in-vivo device within the GI system. If one antenna element receives a relatively weak signal, other antennas of the antenna array may receive a stronger signal but, still, there might be situations where all the antennas receive weak signals due to their unsuitable communication characteristics.
While moving an in-vivo device through the GI system is beneficial, there are some drawbacks associated with conventional antennas that are used to exchange data between the in-vivo device and an external receiver. It would be beneficial to have an extra-body antenna setup that enables receiving signals from the in-vivo device regardless of the location of the device in the GI system/tract.
It would, therefore, be beneficial to be able to provide wearable antenna assembly that would improve communication between a swallowed in-vivo device and an extra-body receiver.